Ex. 3 (5 pts) Consider the following query plan ename (on the fly sort-merge join) scan and keep in main memory scan planeld-100 tig and pipeline) Employees Maintenances clustering index (file scan) on planeld) What is the cost in terms of number of I/Os for this plan? Notes. The result of the left selection, being small, is kept in main memory, where it is sorted. The result of the right selection is pipelined to the join operator, i.e. the generation of the sorted sublists for the first phase of sort is done on the fly Do not count the I/Os for writing the final results (after projection). Consult queryeval.pdf for the table statistics. Ex. 3 (5 pts) Consider the following query plan ename (on the fly sort-merge join) scan and keep in main memory scan planeld-100 tig and pipeline) Employees Maintenances clustering index (file scan) on planeld) What is the cost in terms of number of I/Os for this plan? Notes. The result of the left selection, being small, is kept in main memory, where it is sorted. The result of the right selection is pipelined to the join operator, i.e. the generation of the sorted sublists for the first phase of sort is done on the fly Do not count the I/Os for writing the final results (after projection). Consult queryeval.pdf for the table statistics